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Dec 2024 DOI 10.14302/issn.2835-2165.jfsh-24-5371
One of the primary goals and aims of studying chemistry in society is the promotion of the well-being of humanity and the sustainable utilization of the available resources. Chemistry has played a significant role in water treatment, food production, energy production, and medicine, among other critical areas of society. This study explored the utilization of liquid chromatography-mass spectrometry in the aspect of promoting food safety for human consumption. Various factors might affect the composition and storage of the food items in the society. Through the utilization of chemistry techniques such as (LC-MS), there can be Identification of the various aspects that require consideration in the Improvement of the different health and nutritional requirements that the food items are expected to have in society. As illustrated in this study, the analytical and technical aspects are highly influential in the determination of the proper measures for each component and the illustration of the various toxins that are likely to affect the overall food safety of the members of society in general.
May 2019 DOI 10.14302/issn.2576-6694.jbbs-19-2791
Plants used for medicinal practices which were discovered since prehistoric stone ages are termed Medicinal plants, which are also referred to as medicinal herbs, since plants produces bioactive chemical compounds (phytochemicals), this research however, is concerned with the extraction using Soxhlet extraction technique, phytochemical screening using various test methods, which reveals the presence of anthraquinones (free anthraquinones and combined anthraquinones), carbohydrates, cardiac glycosides, glycosides, flavonoids, saponins, steroids/ terpenes, phenolic compounds and tannins, and absence of alkaloids for extracts of senna occidentalis and also, thin layer chromatography profiling which gives probable foundation for further structural elucidation amongst others. This research shows the presence of potent secondary metabolites present in the leaves of senna occidentalis (leaves).
Dec 2017
p-hydroxybenzoic acid esters are used as food and drug preservatives. These compounds were quantised by a reversed-phase thin-layer chromatography method based on the use of silanized silica gel as stationary phase. Thin layers chromatography of silanized silica gel (HF254) is implemented to separate p-hydroxybenzoic acid and its methyl, ethyl, propyl, butyl and benzyl esters. Borate buffer (pH 2) was used as a mobile phase with the addition of organic solvent as required. For the quantitative determination, the solutions to be analysed were applied in bands on 5 x 20 cm plates. The plates are developed in glass chromatography chambers lined with filter paper. After the plates have been developed they are dried at room temperature. The spots or bands of the various compounds are visualised under a 250-mµ UV light source. The extraction of the silica gel with methanol was effective. Six preservatives were separated with better results for benzyl- and butyl-p-hydroxybenzoates. Chromatographic development controlled by temperature stability in the chromatographic chamber and spectrophotometric determination of all the compounds were indicated. A second development with the same solvent mixture was suggested especially when low RF is involved. Various compounds are completely separated and a good determination of p-hydroxybenzoic acid and its principle esters are possible using a simple technique of elution and spectrophotometric determination.
Nov 2013 DOI 10.14302/issn.2326-0793.jpgr-13-291
A sensitive, specific and rapid high-performance liquid chromatography/tandem mass spectrometry (hplc–ms/ms) method has been developed and validated for the determination of danshensu (dss) in rat plasma in the present study. The analytes were separated on a c18 column (50 mm×2.1 mm, 1.7 μm) and a triplequadrupole mass spectrometry equipped with electrospray ionization (esi) source was applied for detection. The simple protein precipitation was applied to extract dss from the plasma (about 80%). The method was linear over the concentration ranges of 50–1000 ng/ml for dss. The lower limit of quantitation (lloq) of dss was 50 ng/ml. The intra-day and inter-day relative standard deviation (rsd) were less than 15% and the relative error (re) were all within 15%. Finally, the method was successfully applied to support the pharmacokinetic study after guanxinsu solution was orally administrated to the sprague–dawley rat, respectively.
Mar 2013 DOI 10.14302/issn.2328-0182.japst-12-173
A reliable, selective and sensitive liquid chromatography-tandem mass spectrometry (LC-ESI-MS/MS) assay has been proposed for the determination of febuxostat in human plasma using indomethacin as the internal standard (IS). The analyte and IS were extracted from 200 µL of human plasma via liquid-liquid extraction using methyl tert-butyl ether. Chromatography was performed on Hypurity C18 (100 mm × 4.6 mm, 5 µm) column under isocratic conditions. Detection of analyte and IS was done by tandem mass spectrometry, operating in negative ionization and multiple reaction monitoring mode. The deprotonated precursor to product ion transitions monitored for febuxostat and indomethacin were m/z 315.1 →271.0 and 356.1→312.0 respectively. The limit of detection (LOD) and limit of quantitation (LOQ) of the method were 0.0025 µg/mL and 0.05 µg/mL respectively. The linear dynamic range validated for febuxostat was 0.05-6.00 µg/mL. The intra-batch and inter-batch precision (% CV) was ≤ 7.1 % while the mean extraction recovery was > 87 % for febuxostat across quality control levels. The method was successfully applied to a bioequivalence study of 80 mg febuxostat tablet formulation in 14 healthy Indian male subjects under fasting and fed condition. The reproducibility in the measurement of study data was demonstrated by reanalysis of 110 incurred samples.
Jul 2025 DOI 10.14302/issn.2377-2549.jndc-25-5525
A stereoselective synthesis of N-glycosyl amides was studied from available N-glycosyl oxazolines prepared by Ritter-like reactions of protected sugar acetonides. Hydrolysis reactions of the protected pentofuranosyl and hexafuranosyl oxazolines, as precursors of glycosyl amine derivatives, were carried out in the presence of silica gel in chloroform to giveN-α- and β-glycosyl amides in good yields after column chromatography on silica gel. Access to selectively blocked N-α-xylo-, -ribo-, β-arabino-furanosyl, α-glyco-, α-allo-furanosyl, α- and β-galactopyranosyl amides (twelve examples) useful for preparing modified N-glycosides was accomplished through a mild hydrolysis of sugar oxazolines with 2-alkyl substituents in acidic and neutral conditions. To further explore the scope of the BF3.Et2O-mediated approachdeveloped for N-furanosyl oxazolines, a stereoselective synthesis of protected N-α-hexopyranosyl oxazoline was fulfilled in a high yield from d-galactopyranose diacetonide derivative. The Ritter-like promoted reaction between D-arabinose and benzonitrile afforded 2-phenyl-β-d-arabinofurano-(1,2-d)-2-oxazoline as the main product. In acetonitrile the BF3.Et2O-KHF2-assisted reactions of unprotected native sugars were found to result in the formation of mixtures of N-furanosyl and pyranosyl acetamides.
Jun 2023 DOI 10.14302/issn.2377-2549.jndc-23-4615
A literature review was undertaken with a focus on 1) identifying the research gaps regarding CECs, 2) identifying the most common ones, and 3) identifying the typical analytical methods/technologies employed, for their analysis. A total of 214 papers were noted, with a total of 21 review articles (9.8%). Of this total, a surprisingly high number were from South Africa alone: 117 (54.7%), of which 44 (20.6%) reports were associated with South Africa’s Water Research Commission (WRC). The top three CECs research gaps were (decreasing rank: Number of “gaps”, %): 1) Toxicity/Risk/Impact (260, 21.5%), 2) Analysis/Tests/Methods (118, 9.8%) and 2) Future research/studies (118, 9.8%), and 3) Monitoring (89, 7.4%). The common classes of CECs that were reported on, were : (i) Chemical: pharmaceuticals, personal care products, steroids, chlorinated and brominated contaminants, PAHs, PCBs, phthalates, alkyl phenols, herbicides, organochlorine pesticides, engineered nanomaterials and (ii) “Microbiological”: antibiotic resistance genes, human enteric bacteria and viruses, microbial pathogens (e.g., E Coli, rotavirus, Crypto, etc.), infectious biological water contaminants (e.g., E Coli isolates), cyanobacterial blooms (Microcystis). Common test methods used for analysis of the chemical contaminants were found to be chromatography (gas, liquid)-mass spectrometry; for the microbial contaminants, they were culture-based methods, ELISA, fluorescence microscopy, qPCR, RT-qPCR, gel electrophoresis, Raman spectroscopy, and also chromatography (largely liquid)-mass spectrometry, were also used. Some proposals were additionally made to address the very common, significant research gaps noted in CECs research, especially the standardization of analytical chemical test methods, based on chromatography-mass spectrometry, for quantification.
Jun 2023
Insulin is a frequent peptide hormone addition in serum-free mammalian cell culture media. It contributes in a variety of biological functions, including as promoting cell proliferation, cell cycle progression, and glucose uptake. However, it is unknown how stable insulin is under in vitro cell culture media treatment conditions. The instability of insulin in aqueous solutions has caused a number of issues, necessitating the development of new therapeutic strategies that can keep insulin stable and functioning. Such choices are required to accommodate updated insulin delivery guidelines as well as the storage and transportation of insulin. To preserve structural and functional integrity, protein medicines are frequently stabilized with antioxidants in aqueous solutions. In the present study, the effects of the antioxidants disodium ethylenediaminetetraacetic acid dihydrate (EDTA) and sodium selenite (Se) and their ability to scavenge free radicals on insulin stability in the medium Dulbecco's Modified Eagle Medium (DMEM) and Roswell Park Memorial Institute (RPMI) were examined. To investigate the stability of human recombinant insulin, in vitro serum-free DMEM and RPMI media were utilized for 5 days at 37˚C containing different EDTA and Se concentrations. Reversed phase high performance liquid chromatography (RP-HPLC) was used to detect and quantify insulin. Sodium dodecyl sulfate polyacrylamide gel (SDS-PAGE) electrophoresis was used to assess conformational stability. The results demonstrated that, when EDTA and Se were added separately to DMEM and RPMI media, insulin stability was improved compared to when neither compound was added.
Sep 2022 DOI 10.14302/issn.2377-2549.jndc-22-4277
A multistep synthesis of 2-chloro-9-(2′-deoxy-2′-fluoro-β-D-arabinofuranosyl) adenine (clofarabine) is described from methyl β-D-ribofuranoside. A new improved method for preparation of 1,2-diacetyl D-ribofuranose derivative was developed via acetolysis of tri-O-pivaloylated D-ribofuranoside and plausible mechanism of the reaction was proposed. Synthesis of 3′,5′-di-O-pivaloyl-2,6-dichloropurine β-D-riboside along with isomeric 2′,5′-di-O-pivaloyl nucleoside was carried out by stereoselective glycosylation reaction of 2,6-dichloropurine with peracylated D-ribofuranose followed by regioselective 2´-O-deacetylation of protected β-ribonucleoside with different bases. Mild C2′-β-fluorination of the purine 3′,5′-di-O-pivaloyl ribonucleoside with an excess of diethylaminosulfur trifluoride afforded protected 2,6-dichloropurine 2′-fluoro β-D-arabinoside as the key intermediate. Efficient route to clofarabine was also investigated using anion glycosylation of 2-chloroadenine potassium salt with the 1-α-bromide and potassium tert-butoxide in binary solvent mixture, chromatography for separation of a mixture of anomeric nucleosides (a β/α ratio of 3.0:1) and deacylation of benzoylated 2′-fluoro β-nucleoside. Novel N6-isopentyl clofarabine analogue was synthesized by a direct alkylation of the parent nucleoside
Mar 2022 DOI 10.14302/issn.2832-4048.jsm-21-3986
Snake envenomations are responsible for a high percentage of deaths, as these toxic proteins induce severe local and systemic effects. In Brazil, the Bothrops genus is responsible for a satisfactory fraction of accidents, including Bothropsalternatus, recognized as urutu, whose venom is capable of inducing severe myotoxicity. In this work, the BaMtox toxin was purified through a combination of three chromatographic steps, ion exchange in DEAE-Sepharose, affinity in Benzamidine Sepharose 6B columns and reversed-phase HPLC chromatography on a C18 column. The BaMtox toxin has a molecular mass of approximately 14kDa and did not show phospholipase activity or hemorrhage. On the other hand, it induced edema and a significant increase in plasma levels of the creatine kinase enzyme. Thus, the protein called BaMtox is able to induce myotoxicity.
Jun 2021 DOI 10.14302/issn.2377-2549.jndc-21-3740
Millions of people from different countries depend on groundwater, which might contain elevated levels of unhygienic constituents. Poor quality of drinking water in many countries has been forcing people to use bottled water. In the present study, groundwater samples were collected in November 2014 leading to twenty-nine analysis of groundwater samples. The primary objective of this paper is to study the selected groundwater quality parameters as an establishment of preliminary baselines on groundwater constituents. A total of twenty nine water samples were collected (fourteen and fifteen samples from North and South regions of Zanzibar Island respectively. Physical parameters (Turbidity, oxidation-reduction potential ORP, Eh, pH, total dissolved soild TDS, salinity, and Electrical conductivity (EC) were determined in situ using Horiba multiparameters digital meters. Analysis of anions (NO3-, Br- , SO42-, F-, NO2-) was carried out using Ion chromatography (IC). Nitrite and nitrate for some water were below detection limit (BDL) The order of relative abundance for anions in samples collected at Northern region of Zanzibar Island, was NO3- > Br- > SO42- > F- > NO2- , while for the Southern region the order was NO3- >Br- > NO2- > SO42- > F- . In both regions, the orders for other parameters were; Turbidity > pH > salinity; and EC >TDS > ORP > Eh. Almost all the measured parameters were within the WHO guidelines for drinking water. However, for nitrate and bromide, the percentage that exceeded the WHO limit was 7%, and 10.3% respectively. Based on toxicological perspective, although few samples had concentrations above groundwater quality criterion it is fundamental to estimate the intake by humans through the drinking water pathways.
Apr 2021 DOI 10.14302/issn.2689-2855.jan-21-3771
Ascorbic acid is a water-soluble vitamin (Vitamin C) essential for both the plants and animals for the metabolic process. In this study, the liquid chromatography-mass spectrometry (LC-MS) analytical technique was used to characterize the structural properties and isotopic abundance ratio to evaluate the effect of the Trivedi Effect®-Consciousness Energy Healing Treatment on L-ascorbic acid compared to the control sample. The ascorbic acid sample was divided into control and treated parts. Only the treated part received the Trivedi Effect®-Consciousness Energy Healing Treatment remotely by a well-known Biofield Energy Healer, Mahendra Kumar Trivedi. The control and treated samples showed a chromatographic peak at retention time (Rt) 1.8 minutes exhibited the deprotonated molecular ion peak at m/z 175 (M-H)- (calculated for C6H7O6-, 175.02) in the mass spectra. The peak area of the treated sample (12817614.01) was significantly increased by 8.81% compared to the control sample (11779918.9). The LC-MS based isotopic abundance ratio of PM+1/PM (2H/1H or 13C/12C or 17O/16O) in the treated ascorbic acid was significantly increased by 23.22% compared with the control sample. Thus,13C, 2H, and17O contributions from (C6H7O6)- to m/z 176 in the treated ascorbic acid were significantly increased compared with the control sample. The increased isotopic composition of the treated ascorbic acid might have altered the neutron to proton ratio in the nucleus. The changes in isotopic abundance could be due to changes in nuclei possibly through the interference of neutrino particles via the Trivedi Effect®-Consciousness Energy Healing Treatment. The increased isotopic abundance ratio and peak area of the treated ascorbic acid may increase the intra-atomic bond strength and its stability. This novel ascorbic acid after the Trivedi Effect®-Consciousness Energy Healing Treatment would be very useful to design more efficacious pharmaceutical formulations against scurvy, obesity, cardiovascular diseases, hypertension, rheumatoid arthritis, Alzheimer's disease, cancer, etc.
Jul 2020 DOI 10.14302/issn.2377-2549.jndc-20-3460
Laccase enzyme production is important and more beneficial for environment, because it has many roles like, involved in bioremediation, biodegradation, decolorization of environmental polluted dyes and pharmaceutical sector also. Production of laacse enzyme from bacillus sp as using of Agro waste (rice bran) as a substrate. The Agricultural soil sample was collected, after the sample were processed for the preliminary and biochemical tests to identification of Bacillus organism. The Guiacol inducer were used for microbial screening of laccase enzyme production. After that microbial screening, various optimization parameters (pH, Temperature, Inducers, carbon and nitrogen sources) are checked for that production of laccase enzyme in mass level. Based on that optimization the bulk fermentation (large scale) (solid state fermentation) were done as a rice bran substrate. The fermentation product was subjected to analyzed the physiochemical properties and purification based on that techniques of Gel filtration chromatography, Dialysis, Ammonium sulfate preciptation. The protein estimation of that product to analysed by lowry’s method.
Jan 2020 DOI 10.14302/issn.2379-7835.ijn-19-3144
In this study, the antioxidants and photosynthetic compounds of Verdolaga were examined. Compounds were extracted from distinctive segments of the verdolaga using various solvents such as methanol (40, 60, 80%), ethanol (40, 60, 80%), acetone (40, 60, 80%), and deionized water. The use of 80% methanol led to the highest extracted concentration of phenolic substances and flavonoids. The extracted products (Leaves, Stem strips, and Root strips) were evaluated for their radical scavenging capabilities with DPPH (IC50= 22.26, 20.56, and 32.10), and ABTS (IC50= 2.86, 3.70, and 5.24), reducing power (EC50= 15.70, 16.39, and 21.69), and peroxide scavenging activity (1C50= 1.717, 2.937, and 3.255), respectively. The extracted products were analyzed by a gas chromatography-mass spectrometer. Peroxidase, catalase, and polyphenol oxidase assays were completed for the crude extract of verdolaga’s leave, stem strips, and root strips. As indicated by these tests, extracts of the verdolaga’s roots, stems and leaves using 80% methanol yielded high antioxidant activity. The most elevated concentrations of extracted chlorophyll, lycopene, and carotenoids were from the leaves and the highest concentration of extracted tannin was noted from strips of stems. The highest measures of peroxidase and polyphenol oxidase were identified in root strips and the highest units of catalase was identified in leaves.
Oct 2019 DOI 10.14302/issn.2691-6622.ijar-19-2991
The purpose of this study is to evaluate the impact of organic pollution of EL-Mahmodia canal on the fish (Oreochromis niloticus)muscles tissues collected from two sites at EL-Mahmodia canal in summer and winter 2017. EL-Mahmodia canal is exposed to excessive of effluents which impact fish. The present results showed high concentrations of organic pollutants, particularly in winter. Organic pollutants were analyzed using the gas-chromatography-mass spectrometry (GC-MS). A variety of environmental screening studies concerning varieties of water pollutants in Egypt, the target of the present study was to scan the organic pollutants of El-Mahmodia stream at El-Beheira Governorate, Egypt within the muscles of Tilapia fish. Within the present study, it was found that; the analysis of fish muscles in summer season showed a high level of organic pollutants. The organic pollutants that are reported in the muscle of fish in the polluted site were reported as; Dimethomorph-(E), Hexestrol, Diisobutyl phthalate, Diamyl phthalate, Di-n-propyl phthalate, Chlorpyrifos, Phorate sulfoxide, Exaltolide (15-Pentadecanolide), Chlorfenapyr, Pyridate, Ethofumesate, Bis (2-ethylhexyl)phthalate, Dicyclohexyl phthalate, Di-n-octyl phthalate, Tricresylphosphate, meta-, XMC (3, 4-Dimethylphenyl N-methyl, XMC (3,5-Dimethylphenyl N-methyl, Hexestrol, Thymol, Kinoprene, Diisobutyl phthalate, Diisobutyl phthalate, Di-n-hexyl phthalate, Di-n-hexyl phthalate, Carbofuran-3-keto, Tefluthrin, cis-, Carbofuran-7-phenol, Carbofuran, Dicyclohexyl phthalate, Di-n-propyl phthalate, Di-n-propyl phthalate, Bis(2-ethylhexyl)phthalate, Ethofumesate, Hexestrol, Kinoprene, Di-n-hexyl phthalate, Exaltolide (15-Pentadecanolide), Spiroxamine metabolite (4-tert-b), Chlorfenapyr, Tricresylphosphate, para, Tricresylphosphate, meta-, Tricresylphosphate, ortho-, XMC (3, 5-Dimethylphenyl N-methyl, XMC (3,4-Dimethylphenyl N-methyl, Fluroxypyr-1-methylheptyl ester, Cashmeran, Propargite metabolite (Cyclohexa), and Quinoclamine. The present results showed that Diisobutyl phthalate, Bis(2-ethylhexyl)phthalate, Pyridate and Ethofumesate were detected in winter season in the polluted site, whereas, Bis (2-ethylhexyl) phthalate, and Pyridate were the only organic pollutants that were found in winter in the reference site. The accumulation patterns of organic pollutants percentage in the polluted site in summer in the muscles of O. niloticus were in the following order: Chlorpyrifos> Diamyl phthalate> Diisobutylphthalate> Di-n-butylphthalate> Diamyl phthalate> Bis (2-ethylhexyl) phthalate, whereas, in the reference site in summer, it was Chlorpyrifos> Chlorfenapyr> Di-n-butylphthalate> Diisobutylphthalate> Hexestrol> Di-nhexyl phthalate. The accumulation patterns of organic pollutants in the polluted site in winter in the muscles of O. niloticus, were in the following order: Bis(2-ethylhexyl)phthalate> Pyridate> Ethofumesate, whereas in the reference site it was; Bis (2-ethylhexyl)phthalate> Pyridate.
Sep 2019 DOI 10.14302/issn.2471-2140.jaa-19-2997
The paper explores the formation of a-oxoaldehydes during the interaction of glucose metabolites with hydroxyl or alkoxyl radicals. Hydroxyl radicals were generated under radiolysis of aqueous solutions, and alkoxyl radicals (t-BuO) were obtained in the model system tert-butyl hydroperoxide/Fe2+. High-performance liquid chromatography revealed that methylglyoxal was one of the organic products resulting from t-BuO-induced transformations of fructose-1,6-bisphosphate under hypoxic conditions. The interaction of lysine and methylglyoxal one of the main targets of a-oxoaldehydes in proteins was also studied. As chemiluminescence and EPR spectroscopy demonstrated, this reaction generates a methylglyoxal anion radical, a cation-radical of methylglyoxal dialkylamine and a superoxide anion radical. EPR signal of methylglyoxal-derived free radicals was observed in hypoxia, whereas only the trace amounts of these free radicals were recorded in the aerated reaction medium.
Apr 2019 DOI 10.14302/issn.2379-7835.ijn-19-2690
Objective To investigate the major constituents of Tinosporacordifolia Willd. growing on Mangiferaindica, and to evaluate the efficacy of their antibacterial and cytotoxicity activities. Methods The ethanolic stem extract of T. cordifolia was subjected to silica gel 60 column chromatography, thin layer chromatography and medium pressure liquid chromatography for isolation of the major compounds. Identification of purified compounds was achieved by spectroscopic methods.. The crude extract and purified compounds were screened for their antibacterial and cytotoxicity properties using standard procedures. Results Two alkaloids were purified and identified as Magnoflorin (1) and Tembetarine (2). These compounds showed high antibacterial activity against Bacillus cereus and Staphylococcus aureus with both MIC (32-64 µg/ml) and MBC (128-256 µg/ml). The cytotoxicity activity of the purified compounds and crude extract was determined using MTT colorimetric assay against L929 and HEK293 cell lines. This showed weak cytotoxicity activity with IC50 values of 1162.24 to 2290.00 µg/ml and 1376.67 to 2585.06 µg/ml towards L929 and HEK293 cell lines, respectively. Conclusion The major compounds present in ethanolic stem extract of T. cordifolia growing on M. indica were extracted, purified and identified. This study suggests that these compounds exhibit great potential for antibacterial activity with weak cytotoxicity activity. They may be useful for their medicinal functions.
Mar 2019 DOI 10.14302/issn.2471-2140.jaa-19-2699
Xanthine oxidase is a commercially important enzyme with wide area of medical applications to develop diagnostic kits. Xanthine oxidase was extracted, purified and characterized from sheep liver (SLXO). The purification procedure involved acetone precipitation and chromatography on DEAE-cellulose and Sephacryl S-300 columns. The sheep liver xanthine oxidase was homogeneously purified 31.8 folds with 3.5 U/mg specific activity and 24.1% recovery. SLXO native molecular weight was 150 kDa and on SDS-PAGE appeared as single major band of 75 kDa representing a homodimer protein. Isoelectric focusing of the purified SLXO resolved into two closely related isoforms with pI values of 5.6 and 5.8. The apparent Km for xanthine oxidase at optimum pH 7.6 was found to be 0.9 mM xanthine. FeCl2 and NiCl2 increased the activity of SLXO, while CuCl2 and ZnCl2 were found to be potent inhibitors of the purified enzyme. Allopurinol inhibits SLXO competitively with one binding site on the purified molecule and Ki value of 0.06 mM.
Dec 2018 DOI 10.14302/issn.2377-2549.jndc-18-2430
Introduction: Analysis of 8-oxodG is usually conducted by either chromatography-based methods or by immunochemical methods commonly used based upon their low cost and high-throughput. However, concern regarding the accuracy of ELISA methods has complicated their use. We directly compare the levels of urinary 8-oxodG obtained by HPLC-MS/MS with three commercially available ELISA kits in this report. Methods: In the current study, a total of 9 human urine samples were analyzed by LC-MS/MS and three commonly used commercial available ELISA kits. Results: We found that urinary 8-oxodG levels analyzed by HPLC-MS/MS [1.4 ± 0.3 nmol/mmol creatinine) were 7.6- to 23.5-fold lower than those detected by ELISA. Overall, the correlations between ELISA and HPLC-MS/MS were poor but were improved after SPE purification for kits from ENZO (P = 0.2817 without SPE; P = 0.0086 with SPE) and Abcam (P = 0.0596 without SPE; P = 0.0473 with SPE). Discussion and Conclusion: While we confirmed that SPE purification can improve the correlation between the selected ELISA kits and HPLC-MS/MS, HPLC-MS/MS is still the method of choice to accurately assess the levels of 8-oxodG in human urine.
Oct 2018 DOI 10.14302/issn.2328-0182.japst-18-2344
In recent years, the consumption of dietary supplements (DS) has increased worldwide. In Argentina, approximately 14 million DS units were sold between 2015 and 2017. The adulteration of DS with active pharmaceutical ingredients or their analogues has been reported. This represents an alarming emerging risk to public health. The aim of this work was to detect the possible adulteration of a DS marketed in Argentina for the treatment of erectile dysfunction. Initially, thin layer chromatography analysis of the DS capsules content suggested the presence of a major compound. For the isolation and purification of this compound, an easy method consisted of a liquid-liquid extraction (water/CH2Cl2) followed by re-crystallisation from ethanol, is reported. Spectroscopic techniques such as mono- and bidimensional nuclear magnetic resonance, Fourier transform infrared spectroscopy and mass spectrometry allowed its identification as tadalafil. A rapid and reliable method was developed for the quantification of tadalafil in this DS by high performance liquid chromatography-mass spectrometry (HPLC-MS/MS). The mean content of tadalafil per capsule was 21.2 mg which represents a slightly higher value than that found in approved products in Argentina (5 or 20 mg per tablet). In addition, an undeclared alga was identified in the DS by microscopic techniques.
May 2018 DOI 10.14302/issn.2835-513X.ijl-18-2122
Membrane dynamics in the presynaptic region of the neuron is a key process of neuronal signal transduction. Dynamin plays a central part during endocytosis participating in the deformation of membrane structure and constriction. During the study of molecular interaction of presynaptic proteins, we found that dynamin fraction prepared from brain extract contains several lipid components. Fractionation of lipids with thin layer chromatography and mass-analysis showed the presence of phosphatidylcholine, phosphatidylethanolamine, cerebroside, cholesterol and its-derivatives, and triacylglycerol. Since the GTPase activity of bacterially expressed dynamin was activated by the extracted lipid fraction, lipid components that affect the GTPase activity of dynamin was screened and cerebroside, hydroxycholesterols, cholesterol, and triacylglycerol were found to activate the GTPase activity. This result not only suggests the possibility that several neutral lipids participate in the membrane dynamics, but also revealed the possibility that a protein fraction contains lipid components even if its purity was confirmed with SDS-PAGE.
Nov 2017 DOI 10.14302/issn.2641-7669.ject-17-1790
Solvent residue such as hexane in foodstuff, especially edible oil could be considered as the undesirable substances when exceeds maximum residue limit (MRL). The aim of this study is to determine the hexane content in various brands of edible oils. Totally forty samples (23 brands) of different types of vegetable oils including frying oils (n=14), blended oils (n=13), sunflower oils (n=6), corn oils (n=5) and canola oils (n=2) from Iran´s market were analyzed for hexane content using solid phase microextraction gas chromatography equipped with a flame-ionization detector (SPME)-GC-(FID). The hexane residue was detected in thirty-six out of forty examined samples, ranged from lower than LOD to 42.6 µg/kg. However, in all of them hexane content were below the MRL of 1 mg/kg which set by the European Union.
May 2016 DOI 10.14302/issn.2377-2549.jndc-15-923
A hybrid monolithic column was prepared using octavinyloctasilasesquioxane (OVS) as a monomer, benzoyl peroxide/dimethylacetamide (BPO/DMA) as initiator, ethylene glycol dimethacrylate (EDMA) as cross-linker, 1-dodecanol as porogenic agent and dimethylbenzene as cosolvent. A tidy skeleton, much bigger specific surface area (22.4 m2/g) and lower swelling property of the monolithic column with OVS added than the one without OVS added were determined with Scanning Electron Microscopy (SEM), Nitrogen adsorption/desorption measurements (BET) and swelling test with elute of different concentration of acetonitrile in water. Fourier-transform infrared spectra (FTIR) was taken to characterize the composition of groups. Moreover, a better separation performance for benzene series compounds under reversed phase liquid chromatography (RPLC) mode was obtained using the monolithic columns with OVS added than those without.
Feb 2016 DOI 10.14302/issn.2379-7835.ijn-14-478
In this study, chemical composition of Barberry integerrima seed and physicochemical properties and fatty acids composition of its oil were determined. The seeds contained 11.4 % oil and protein, moisture, crude fiber and ash contents were 17.0%, 19.1%, 48.8% and 2.9%, respectively. The main fatty acids recognized by gas chromatography were linolenic (ω-3), linoleic (ω-6) and oleic (ω-9) acid (38.3, 37.0, 15.5%, respectively). The density and refractive index of the extracted barberry seed oil were 0.821 and 1.4780, respectively. FFA (% as oleic acid), acid value (mg KOH/g oil), iodine value (g I2/100 g oil), saponification number (mg KOH/ g oil), and unsaponifiable matter content (%) of the extracted oil from Barberry integerrima seeds were 0.70, 1.4, 180.0, 197.2, and 2.3, respectively. Color of extracted crude oil exhibited red unit 4.9, yellow unit 18.6 and blue unit 1.9, respectively. Total phenolics compounds (mg Gallic acid/kg oil), total tocopherols (mg/kg oil) and total sterols (mg/100g oil), were 323.0, 111.1 and 762.3, respectively. Specific extinctions at 232 nm (K232) and 270 nm (K270) and R-value (K232/K270) were 3.9, 2.2 and 1.8, respectively. The present study revealed that Barberry integerrima seed oil can be a valuable source of oil for food, pharmaceutics and cosmetics uses.